Light emitting device and light emitting device package

ABSTRACT

Disclosed are a light emitting device and a light emitting device package. The light emitting device includes a light emitting structure including a first conductive semiconductor layer, an active layer on the first conductive semiconductor layer, and a second conductive semiconductor layer on the active layer, an adhesive layer contacting a top surface of the first conductive semiconductor layer, a first electrode contacting a top surface of the first conductive semiconductor and a top surface of the adhesive layer, and a second electrode contacting the second conductive semiconductor layer, wherein the adhesive layer contacting the first electrode is spaced apart from the second electrode.

The present application is a continuation of a pending U.S. applicationSer. No. 13/014,390 filed on Jan. 26, 2011, which claims priority ofKorean Patent Application No. 10-2010-0022754 filed on Mar. 15, 2010,which is hereby incorporated by reference in its entirety.

BACKGROUND

The embodiment relates to a light emitting device and a light emittingdevice package.

Light emitting diodes (LEDs) are a kind of semiconductor devices thatconvert electric energy into light. The LED is advantageous as comparedwith conventional light sources, such as a fluorescent lamp or a glowlamp, in terms of power consumption, life span, response speed, safetyand environmental-friendly requirement. In this regard, various studieshave been performed to replace the conventional light sources with theLEDs. The LEDs are increasingly used as light sources for lightingdevices such as various lamps, liquid crystal displays, electricsignboards, and street lamps.

SUMMARY

The embodiment provides a light emitting device having a novel structureand a lighting emitting device package.

The embodiment provides a light emitting device capable of improvingreliability and a light emitting device package.

According to the embodiment, a light emitting device includes alightemitting structure including a first conductive semiconductor layer, anactive layer on the first conductive semiconductor layer, and a secondconductive semiconductor layer on the active layer, an adhesive layercontacting a top surface of the first conductive semiconductor layer, afirst electrode contacting a top surface of the first conductivesemiconductor and a top surface of the adhesive layer, and a secondelectrode contacting the second conductive semiconductor layer, whereinthe adhesive layer contacting the first electrode is spaced apart fromthe second electrode.

According to the embodiment, a light emitting device includes aconductive support member, a light emitting structure including a firstconductive semiconductor layer, an active layer, and a second conductivesemiconductor layer on the conductive support member, an adhesive layercontacting a top surface of the light emitting structure, and anelectrode contacting a top surface of the adhesive layer and a topsurface of the light emitting structure.

According to the embodiment, the light emitting device package includesa body, a light emitting device on the body, and a molding membersurrounding the light emitting device. The light emitting deviceincludes a body, a light emitting device on the body, and a moldingmember surrounding the light emitting device, wherein the light emittingdevice includes a light emitting structure including a first conductivesemiconductor layer, an active layer, and a second conductivesemiconductor layer, an adhesive layer contacting a top surface of thefirst conductive semiconductor layer, a first electrode contacting a topsurface of the first conductive semiconductor and a top surface of theadhesive layer, and a second electrode contacting to the secondconductive semiconductor layer, and wherein the adhesive layercontacting the first electrode is spaced apart from the secondelectrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a light emitting device according toa first embodiment;

FIG. 2 is a plan view showing the light emitting device of FIG. 1;

FIG. 3 is an enlarged view of a region A of the light emitting device ofFIG. 1;

FIG. 4 is a sectional view showing a light emitting device according toa second embodiment;

FIG. 5 is a sectional view showing a light emitting device according toa third embodiment;

FIG. 6 is a sectional view showing a light emitting device according toa fourth embodiment;

FIGS. 7 to 11 are views showing the manufacturing process of the lightemitting device according to the first embodiment;

FIG. 12 is a sectional view showing a light emitting device according toa fifth embodiment;

FIGS. 13 to 20 are views showing the manufacturing process of the lightemitting device according to the fifth embodiment;

FIG. 21 is a sectional view showing a light emitting device packageincluding a light emitting device according to the embodiment;

FIG. 22 is an exploded perspective view showing a display apparatusaccording to the embodiment;

FIG. 23 is a view showing a display apparatus according to theembodiment; and

FIG. 24 is a perspective view showing a lighting device according to theembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of the embodiments, it will be understood that, whena layer (or film), a region, a pattern, or a structure is referred to asbeing “on” or “under” another substrate, another layer (or film),another region, another pad, or another pattern, it can be “directly” or“indirectly” over the other substrate, layer (or film), region, pad, orpattern, or one or more intervening layers may also be present. Such aposition of the layer has been described with reference to the drawings.

The thickness and size of each layer shown in the drawings may beexaggerated, omitted or schematically drawn for the purpose ofconvenience or clarity. In addition, the size of elements does notutterly reflect an actual size.

FIG. 1 is a sectional view showing a light emitting device 100 accordingto a first embodiment, FIG. 2 is a plan view showing the light emittingdevice of FIG. 1, and FIG. 3 is an enlarged view of a region A of thelight emitting device of FIG. 1.

Referring to FIGS. 1 to 3, the light emitting device 100 according tothe first embodiment includes a growth substrate 105, a light emittingstructure 110 formed by sequentially stacking a first conductivesemiconductor layer 112, an active layer 114, and a second conductivesemiconductor layer 116 on the growth substrate 105, and having a regionS in which a top surface of the first conductive semiconductor layer 112is exposed, an adhesive layer 130 allowing at least a portion of the topsurface of the first conductive semiconductor layer 112 in the region Sto be exposed, a first electrode 150 formed on both the first conductivesemiconductor layer 112 of the region S and the adhesive layer 130, atransmissive electrode layer 120 formed on the second conductivesemiconductor layer 116, and a second electrode 140 formed on both ofthe second conductive semiconductor layer 116 and the transmissiveelectrode layer 120.

The growth substrate 105 may include at least one selected from thegroup consisting of single crystalline sapphire (Al₂O₃), SiC, GaAs, GaN,ZnO, Si, GaP, InP, Ge, SiGe, but the embodiment is not limited thereto.

The growth substrate 105 may be provided on a top surface thereof with apredetermined pattern or may be inclined to accelerate the growth of thelight emitting structure 110 and improve the light emission efficiencyof the light emitting device, but the embodiment is not limited thereto.

The light emitting structure 110 may be grown from the growth substrate105.

The light emitting structure 110 may include the first conductivesemiconductor layer 112, the active layer 114, and the second conductivesemiconductor layer 116. A buffer layer or an undoped semiconductorlayer may be disposed between the growth substrate 105 and the lightemitting structure 110 to reduce lattice constant mismatch between thegrowth substrate 105 and the light emitting structure 110 or improve thecrystalline of the light emitting structure 110.

For example, the first conductive semiconductor layer 112 may include anN type semiconductor layer doped with N type dopants. The N typesemiconductor layer may include a semiconductor material having acompositional formula of In_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1,0≦x+y≦1). For example, the N type semiconductor layer may be selectedfrom the group consisting of InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, andInN, and may be doped with N type dopants such as Si, Ge, or Sn.

If the active layer 114 has a quantum well structure, the active layer114 may have a single quantum well structure having a well layer havinga compositional formula of InxAlyGa1-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1), and abarrier layer having a compositional formula of InaAlbGa1-a-bN (0≦a≦1,0≦b≦1, 0≦a+b≦1). The well layer may include material having energybandgap lower than that of the barrier layer.

The active layer 114 may generate light by energy generated in therecombination of the electrons and the holes provided from the first andsecond conductive semiconductor layers 112 and 116.

For example, the second conductive semiconductor layer 116 may include aP type semiconductor including P type dopants. The P type semiconductorlayer may include a semiconductor material having a compositionalformula of In_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). For example,the P type semiconductor layer may be selected from the group consistingof InAlGaN, GaN, AlGaN, AlInN, InGaN, AlN, and InN. The P typesemiconductor layer may be doped with P type dopants such as Mg, Zn, Ca,Sr, and Ba.

The buffer layer (not shown) and the undoped semiconductor layer (notshown) may include a semiconductor material having a compositionalformula of In_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). For example,the buffer layer (not shown) and the undoped semiconductor layer may beselected from the group consisting of InAlGaN, GaN, AlGaN, AlInN, InGaN,AlN, and InN. The buffer layer and the undoped semiconductor layer arenot doped with conductive dopants. Accordingly, the buffer layer and theundoped semiconductor layer may have electrical conductivity remarkablylower than that of the first and second conductive semiconductor layers112 and 116.

The transmissive electrode layer 120 may be formed on the secondconductive semiconductor layer 116 of the light emitting structure. Thetransmissive electrode layer 120 spreads current, so that the currentcan be prevented from being centralized around the second electrode 140.

The transmissive electrode layer 120 may have a single layer structureor a multiple layer structure including at least one selected from thegroup consisting of ITO (indium tin oxide), IZO (indium zinc oxide),IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO(indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO(aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zincoxide), IrOx, RuOx, Ni, Ag, and Au.

As shown in FIG. 1, the transmissive electrode layer 120 exposes atleast a portion of the second conductive semiconductor layer 116. Thetransmissive electrode layer 120 may be actually formed throughout thewhole top surface of the second conductive semiconductor layer 116, butthe embodiment is not limited thereto.

The second electrode 140 may be formed one of the transmissive electrodelayer 120 and the second conductive semiconductor layer 116, or may beformed on both of the transmissive electrode layer 120 and the secondconductive semiconductor layer 116.

The second electrode 140 may supply power to the light emittingstructure 110 together with the first electrode 150.

For example, the second electrode 140 may have a single layer structureor a multiple layer structure including at least one selected from thegroup consisting of Au, Al, Ag, Ti, Cu, Ni, and Cr, but the embodimentis not limited thereto.

In the region S of the light emitting structure 110, a portion of thetop surface of the first conductive semiconductor layer 112 is exposedthrough the Mesa-Etching process. The region S may be formed at aportion of lateral surfaces of the light emitting structure 110.

The adhesive layer 130 may be formed on the top surface of the firstconductive semiconductor layer 112 of the region S in such a manner thatat least a portion of the top surface of the first conductivesemiconductor layer 112 can be exposed.

In other words, at least a portion of the adhesive layer 130 may overlapwith the first electrode 150 in a vertical direction. The adhesive layer130 improves the adhesive strength between the first conductivesemiconductor layer 112 and the first electrode 150, so that thereliability for the light emitting device 100 can be improved.

The reliability can be acquired because the adhesive strength betweenthe first electrode 150 and the adhesive layer 130 and the adhesivestrength between the adhesive layer 130 and the first conductivesemiconductor layer 112 are greater than the adhesive strength betweenthe first conductive semiconductor layer 112 and the first electrode150. Preferably, in order to maximize the above effect, at leastportions of the first electrode 150 and the adhesive layer 130perpendicularly overlap with each other.

Referring to FIG. 3, the width (2*b) of a bottom surface of the firstelectrode 150 perpendicularly overlapping with the adhesive layer 130may correspond to 5% to 90% of the whole width (a) of a top surface ofthe first electrode 150. The overlap area between the first electrode150 and the first conductive semiconductor layer 112 may correspond to10% to 95% of the whole area (a) of the top surface of the firstelectrode 150. The adhesive layer 130 is embedded between the firstelectrode 150 and the first conductive semiconductor layer 112, and thisstructure can improve the extraction efficiency of light travelingtoward the first electrode 150.

In order to more firmly bond the adhesive layer 130 between the firstelectrode 150 and the first conductive semiconductor layer 112, aconcave-convex pattern is formed on top and bottom surfaces of theadhesive layer 130, so that the surface area of the adhesive layer 130can be maximized.

The adhesive layer 130 preferably includes a material having arefractive index lower than that of the light emitting structure 110 toimprove the light extraction efficiency.

The transmissive insulating material of the adhesive layer 130 mayinclude at least one selected from the group consisting of SiO₂,SiO_(x), SiO_(x)N_(y), Si₃N₄, TiO₂, and Al₂O₃. The adhesive layer 130may have a multiple layer structure including different materials. Ifthe adhesive layer 130 has a multiple layer structure, the adhesivelayer 130 may have a repeated stack structure of a first layer includinga material (e.g., Al₂O₃) having a high refractive index of 1.7 to 1.8and a second layer including a material (SiO₂) having low refractiveindex of 1.5 to 1.6.

The adhesive layer 130 may include transmissive conductive material. Theadhesive layer 130 may have a multiple layer structure formed bystacking a second layer including a transmissive conductive material ona first layer including the transmissive insulating material. Theadhesive layer 130 may have a thickness to the extent that theelectrical operation of the light emitting structure is not affected bythe thickness. The transmissive conductive material may have a singlelayer structure or a multiple layer structure including at least oneselected from the group consisting of ITO (indium tin oxide), IZO(indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminumzinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tinoxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO(gallium zinc oxide), IrO_(x) and RuO_(x). In this case, the refractiveindex of the ITO is about 2.5.

In addition, the adhesive layer 130 is formed by stacking a first layerhaving a high refractive index and a second layer having a lowrefractive index by using transmissive insulating material andtransmissive conductive material. If the difference between the tworefractive indexes is less than the refractive index of light emittingstructure, an inverse stack structure is formed. In other words, thesecond layer having a low refractive index and the first layer having ahigh refractive index are sequentially stacked.

Meanwhile, the adhesive layer 130 may have various shapes. FIGS. 4 to 6are sectional views showing a light emitting device according to thesecond embodiment to the fourth embodiment.

Referring to FIGS. 1 to 3, in the light emitting device 100 according tothe first embodiment, the adhesive layer 130 may overlap with thelateral surface of the light emitting structure 110, for example, thelateral surface of the active layer 114, the lateral surface of thesecond conductive semiconductor layer 116, and a portion of the topsurface of the transmissive electrode layer 120, as well as the topsurface of the first conductive semiconductor layer 112 of the region S.

Referring to FIG. 4, in a light emitting device 100A according to thesecond embodiment, the adhesive layer 130 may overlap with the lateralsurface of the light emitting structure 110, for example, the lateralsurface of the active layer 114, the lateral surface of the secondconductive semiconductor layer 116, and a portion of the top surface ofthe second conductive semiconductor layer 116, as well as at the topsurface of the first conductive layer 112 of the region S. In this case,the transmissive electrode layer 120 may be formed on the secondconductive semiconductor layer 116 in such a manner that thetransmissive electrode layer 120 is spaced apart from one end of theadhesive layer 130 formed on the second conductive semiconductor layer116.

Referring to FIG. 5, in a light emitting device 100B according to thethird embodiment, the adhesive layer 130 may be formed only on the topsurface of the first conductive semiconductor layer 112 of the region S.

Referring to FIG. 6, in a light emitting device 100C according to afourth embodiment, the adhesive layer 130 may overlap with the lateralsurface of the light emitting structure 110, for example, the lateralsurface of the active layer 114, the lateral surface of the secondconductive semiconductor layer 116, and a portion of the top surface ofthe second conductive semiconductor layer 116, as well as the topsurface of the first conductive semiconductor layer 112. In this case,the transmissive electrode layer 120 may be not only formed on thesecond conductive semiconductor layer 116, but on one end of theadhesive layer 130 on the second conductive semiconductor layer 116. Inother words, one end of the transmissive electrode layer 120 may overlapwith one end of the adhesive layer 130.

In the light emitting devices 100, 100A, and 100C according to thefirst, second, and fourth embodiments, since the adhesive layer 130simultaneously contacts the first conductive semiconductor layer 112,the active layer 114, and the second conductive semiconductor layer 116,the adhesive layer 130 has to include transmissive insulating materialto prevent electrical short between the layers 112, 114, and 116.

Ina light emitting device 100B according to a third embodiment, sincethe adhesive layer 130 is formed at an upper portion of the firstconductive semiconductor layer 112, electrical short does not occur.Accordingly, the adhesive layer 130 may include transmissive conductivematerial or transmissive insulating material. The adhesive layer 130 mayhave a single layer structure or a multiple layer structure includingSiO₂, SiO_(x), SiO_(x)N_(y), Si₃N₄, TiO₂, Al₂O₃, ITO (indium tin oxide),IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indiumaluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indiumgallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide),GZO (gallium zinc oxide), IrO_(x) and RuO_(x).

The first electrode 150 may be formed on the adhesive layer 130 and thefirst conductive semiconductor layer 112. A portion of a bottom surfaceof the first electrode 150 contacts the top surface of the firstconductive semiconductor layer 112, and a remaining portion of thebottom surface of the first electrode 150 can contact the top andlateral surfaces of the adhesive layer 130. The first electrode 150 mayhave a single layer structure or a multiple layer structure including atleast one selected from the group consisting of Au, Al, Ag, Ti, Cu, Ni,and Cr, but the embodiment is not limited thereto.

If the first electrode 150 has a multiple layer structure, the lowermost layer of the first electrode 150, which is adjacent to theinterface between the first electrode 150 and the first conductivesemiconductor layer 112 or the adhesive layer 130, preferably includesTi, Ni, or Cr representing high adhesive strength. In addition, theupper most layer of the first electrode 150 preferably includes Au or Tirepresenting high adhesive strength so that wire bonding can easilyperformed.

Hereinafter, the manufacturing process of the light emitting device 100according to the first embodiment will be described in detail.

FIGS. 7 to 11 are views showing the manufacturing process of a lightemitting device according to the first embodiment.

Referring to FIG. 7, the light emitting structure 110 may be formed bysequentially forming the first conductive semiconductor layer 112, theactive layer 114, and the second conductive semiconductor layer 116 onthe growth substrate 105.

The light emitting structure 110 may be formed through MOCVID (MetalOrganic Chemical Vapor Deposition), CVD (Chemical Vapor Deposition),PECVD (Plasma-Enhanced Chemical Vapor Deposition), MBE (Molecular BeamEpitaxy), or HVPE (Hydride Vapor Phase Epitaxy), but the embodiment isnot limited thereto.

Referring to FIG. 8, a mesa etching is performed with respect to aportion of a corner of the light emitting structure 110, that is, regionS such that at least a portion of the top surface of the firstconductive semiconductor layer 112 is exposed.

After forming a pattern for etching on the light emitting structure 110through a photolithography process, the mesa etching is performed byemploying the pattern as a mask. The mesa etching process may include adry etching process or a wet etching process.

Referring to FIG. 9, the transmissive electrode layer 120 may be formedon the second conductive semiconductor layer 116.

The transmissive electrode layer 120 may be formed on the entire portionof the top surface of the second conductive semiconductor layer 116 or aportion of the second conductive semiconductor layer 116.

The transmissive electrode layer 120 may be formed through one of E-beamdeposition, sputtering, and PECVD (Plasma Enhanced Chemical VaporDeposition), but the embodiment is not limited thereto.

Referring to FIG. 10, the adhesive layer 130 may be formed on at leastthe top surface of the first conductive semiconductor layer 112 of theregion S. The adhesive layer 130 may be formed on the top surface andthe lateral surface of the first conductive semiconductor layer 112, thelateral surface of the active layer 114, and the lateral surface and thetop surface of the second conductive semiconductor layer 116. In thiscase, one end of the adhesive layer 130 may be formed at a portion ofthe top surface of the second conductive semiconductor layer 116.

The adhesive layer 130 may expose at least a portion of the top surfaceof the first conductive semiconductor layer 112.

After the mask has been formed, the adhesive layer 130 may be formedthrough E-beam deposition, sputtering, and PECVD (Plasma EnhancedChemical Vapor Deposition), but the embodiment is not limited thereto.

The adhesive layer 130 may be patterned through an etching process suchthat the second electrode 140 contacts the first conductivesemiconductor layer 112.

Referring to FIG. 11, the first electrode 150 is formed on the firstconductive semiconductor layer 112 and the adhesive layer 130, and thesecond electrode 140 is formed on the second conductive semiconductorlayer 116 and the transmissive electrode layer 120, thereby providingthe light emitting device 100 according to the first embodiment. Aportion of the bottom surface of the first electrode 150 may be formedon the first conductive semiconductor layer 112, and a remaining portionof the bottom surface of the first electrode 150 may be formed on theadhesive layer 130. A portion of the second electrode 140 may be formedon the second conductive semiconductor layer 116, and a remainingportion of the second electrode 140 may be formed on the transmissiveelectrode layer 120.

The first and second electrodes 140 and 150 may be formed through adeposition scheme or a plating scheme, but the embodiment is not limitedthereto.

Hereinafter, a light emitting device according to the fifth embodimentwill be described in detail, and the structures and components identicalto those of the previous embodiments will be not further described orwill be briefly described.

FIG. 12 is a sectional view showing a light emitting device according toa fifth embodiment.

Referring to FIG. 12, a light emitting device 200 according to a fifthembodiment includes a conductive support member 240, an adhesivemetallic layer 245 on the conductive support member 240, a reflectivelayer 246 on the adhesive metallic layer 245, an ohmic layer 248 on thereflective layer 246, a protection layer 247 on an outer peripheralportion of a top surface of the reflective layer 246, a light emittingstructure 210 on the ohmic layer 248 and the protection layer 247, apassivation layer 235 on a lateral surface of the light emittingstructure 210, an adhesive layer 230 on a top surface of the lightemitting structure 210, and an electrode 250 on the light emittingstructure 210 and the adhesive layer 230.

The conductive support member 240 supports the light emitting structure210. The conductive support member 240 acts as an electrode to supplypower to the light emitting device 200 together with the electrode 250.For example, the conductive support member 240 may include at least oneselected from the group consisting of copper (Cu), gold (Au), nickel(Ni), molybdenum (Mo), copper-tungsten (Cu—W), and a carrier-wafer(including Si, Ge, GaAs, ZnO, SiC, or SiSe).

The adhesive metallic layer 245 may be formed on the conductive supportmember 240. The adhesive metallic layer 245 may include metallicmaterial representing superior adhesive strength in order to improveinterfacial adhesive strength between the conductive support member 240and the reflective layer 246. For example, the adhesive metallic layer245 may have a single layer structure or a multiple layer structureincluding at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag and Ta.However, if the conductive support member 240 is formed through aplating or deposition scheme instead of a bonding scheme, the adhesivemetallic layer 245 may be not formed.

The reflective layer 246 may be formed on the adhesive metallic layer245. The reflective layer 246 reflects upward light incident from thelight emitting structure 210 so that the light emission efficiency ofthe light emitting device 200 can be improved. For example, thereflective layer 246 may include metal including at least one of silver(Ag), aluminum (Al), palladium (Pd), copper (Cu), and platinum (Pt) orthe alloy thereof.

The ohmic layer 248 may be formed on the reflective layer 246. The ohmiclayer 248 may be formed to form the ohmic contact between the reflectivelayer 246 and the light emitting structure 210.

The ohmic layer 248 may selectively include a transmissive conductivelayer or metal. The ohmic layer 248 may have a single layer structure ora multiple layer structure including at least one of ITO, IZO, IZTO,IAZO, IGZO, IGTO, AZO, ATO, GZO, IrOx, RuOx, Ni, Ag and Au.

The protection layer 247 may be formed at an outer peripheral portion ofthe top surface of the reflective layer 246. In other words, theprotection layer 247 may be formed at an outer peripheral portionbetween the light emitting structure 210 and the conductive supportmember 240.

The protection layer 247 prevents the conductive support member 240 frombeing electrically shorted with the light emitting structure 210, sothat the reliability for the manufacturing process can be improved.

For example, the protection layer 247 may include electricallyinsulating material or material having electrical conductivity lowerthan that of the light emitting structure 210. For example, theprotection layer 247 may include at least one selected from the groupconsisting of SiO₂, Si_(x)O_(y), Si₃N₄, Si_(x)N_(y), SiO_(x)N_(y),Al₂O₃, TiO₂, ITO, AZO, and ZnO.

A current blocking layer 249 may be disposed between the ohmic contactlayer 248 and the light emitting structure 210 such that at least aportion of the current blocking layer 249 perpendicularly overlaps withthe electrode 250. The current blocking layer 249 can prevent currentfrom being concentrated on the shortest distance between the electrode250 and the conductive support member 240.

The current blocking layer 249 may include electrical insulatingmaterial, or material forming schottky contact with a second conductivesemiconductor layer 216. For example, the current blocking layer 249 mayinclude at least one selected from the group consisting of ZnO, SiO₂,SiO_(x), SiO_(x)N_(y), Si₃N₄, Al₂O₃, TiO_(x), Ti, Al, and Cr.

The light emitting structure 210 may be formed on the ohmic contactlayer 248 and the protection layer 247. The light emitting structure 210includes a first conductive semiconductor layer 216, an active layer 214on the first conductive semiconductor layer 216, and a second conductivesemiconductor layer 212 on the active layer 214, but the embodiment isnot limited thereto.

The light emitting structure 210 may include group III to V compoundsemiconductors, and may generate light through the recombination ofelectrons and holes. Since the light generation through therecombination of the electrons and holes has been described above, thedetails thereof will be omitted.

A roughness structure or a concave-convex structure may be formed on atop surface of the light emitting structure 210, that is, a top surfaceof the second conductive semiconductor layer 212. The roughnessstructure or the concave-convex structure may include roughness having arandom shape formed through a wet etching process, or a periodicalpattern such as a photonic crystal structure formed through a patterningprocess.

The roughness structure or the concave-convex structure can improve thelight extraction efficiency of the light emitting structure 200. Inaddition, the roughness structure or the concave-convex structure widensthe surface area of the interface between the light emitting structure210 and the adhesive layer 230, so that the adhesive strength betweenthe light emitting structure 210 and the adhesive layer 230 can beimproved.

The passivation layer 235 may be formed on a lateral surface of thelight emitting structure 210. The passivation layer 235 can prevent thelight emitting structure 210 from being electrically shorted with anexternal electrode. For example, the passivation layer 235 may beselected from the group consisting of SiO₂, SiO_(x), SiO_(x)N_(y),Si₃N₄, and Al₂O₃, but the embodiment is not limited thereto.

The adhesive layer 230 may be formed on at least a portion of the topsurface of the light emitting structure 210. As shown in FIG. 12, theadhesive layer 230 may expose the portion of the top surface of thesecond conductive semiconductor layer 212. The adhesive layer 230 mayinclude material the same as that of the passivation layer 235. Theadhesive layer 230 and the passivation layer 235 may be integral witheach other while being formed simultaneously through the same process.The adhesive layer 230 may extend from the passivation layer 235. Theadhesive layer 230 and the passivation layer 235 may include differentmaterials and be formed through different processes in such a mannerthat the adhesive layer 230 is spaced apart from the passivation layer235.

The electrode 250 may be formed on a portion of a top surface of theadhesive layer 230 and a portion of a top surface of the secondconductive semiconductor layer 212. In other words, a portion of abottom surface of the electrode 250 overlaps with a top surface of thesecond conductive semiconductor layer 212, and a remaining portion ofthe bottom surface of the electrode 250 overlaps with the adhesive layer230.

The adhesive layer 230 improves the adhesive strength between the secondconductive semiconductor layer 212 and the electrode 250, so that thereliability for the light emitting device 200 can be improved.

The reliability can be acquired because the adhesive strength betweenthe electrode 250 and the adhesive layer 230 and the adhesive strengthbetween the adhesive layer 230 and the second conductive semiconductorlayer 212 are greater than the adhesive strength between the secondconductive semiconductor layer 212 and the electrode 250.

In order to maximize the above effect, at least portions of theelectrode 250 and the adhesive layer 230 perpendicularly overlap witheach other. The width of the bottom surface of the electrode 250perpendicularly overlapping with the adhesive layer 230 may correspondto 5% to 90% of the whole width of the top surface of the electrode 250.The overlap area between the electrode 250 and the second conductivesemiconductor layer 212 may correspond to 10% to 95% of the area of thetop surface of the electrode 250. A concave-convex structure or theroughness structure are formed on the top surface and the bottom surfaceof the adhesive layer 230 to increase the surface area of the adhesivelayer 230 such that the adhesive layer 230 can more firmly bond theelectrode 250 to the second conductive semiconductor layer 212.

The adhesive layer 230 may have a single layer structure or a multiplelayer structure including at least one selected from the groupconsisting of, SiO₂, SiO_(x), SiO_(x)N_(y), Si₃N₄, TiO₂, Al₂O₃, ITO,IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO, IrO_(x), and RuO_(x), butthe embodiment is not limited thereto.

Preferably, the adhesive layer 230 include a material having arefractive index lower than that of the light emitting structure 210 sothat light extraction efficiency can be improved.

The electrode 250 may be formed on both of the second conductivesemiconductor layer 212 and the adhesive layer 230. The bottom surfaceof the electrode 250 contacts the top surface and the lateral surface ofthe adhesive layer 230 while surrounding the top surface and the lateralsurface of the adhesive layer 230. Accordingly, the electrode 250 mayfirmly contact the top surface of the light emitting structure 210.

Hereinafter, the method of manufacturing the light emitting deviceaccording to the fifth embodiment will be described, and the structuresand components identical to those of the previous embodiments will benot further described or will be briefly described.

FIGS. 13 to 20 are views showing the manufacturing process of the lightemitting device according to the fifth embodiment.

Referring to FIG. 13, the light emitting structure 210 may be formed ona growth substrate 205. The light emitting structure 210 may include atleast the second conductive semiconductor layer 212, the active layer214, and the first conductive semiconductor layer 216.

Referring to FIG. 14, the protection layer 247 and the current blockinglayer 249 may be formed on the first conductive semiconductor layer 216of the light emitting structure 210.

The protection layer 247 may be formed at a boundary region of anindividual chip (1 chip) by using a mask pattern, and may have a ringshape, a loop shape, or a frame shape. For example, the protection layer247 may be formed through one of an E-beam deposition scheme, asputtering scheme, and a PECVD (Plasma Enhanced Chemical VaporDeposition).

At least a portion of the current blocking layer 249 may overlap withthe electrode 250, which will be formed later, perpendicularly to theelectrode 250. The current blocking layer 249 may be formed through adeposition scheme or a plating scheme.

Referring to FIG. 15, the ohmic layer 248 may be formed on both of thefirst conductive semiconductor layer 216 and the current blocking layer249, and the reflective layer 246 may be formed on the ohmic layer 248and the protection layer 247. The adhesive metallic layer 245 may beformed on the reflective layer 246, and the conductive support member240 may be formed on the adhesive metallic layer 245.

The ohmic layer 248 and the reflective layer 246 may be formed through adeposition scheme or a plating scheme.

The conductive support member 240 may be formed through a depositionscheme or a plating scheme, or may be additionally prepared in the formof a sheet and bonded. If the conductive support member 240 is formedthrough the deposition or plating scheme, the adhesive metallic layer245 may be not formed.

Referring to FIG. 16, the growth substrate 205 may be removed. Thegrowth substrate 205 may be removed through at least one of a LLO (LaserLift Off) process and a CLO (Chemical Lift Off) process.

The LLO process is to irradiate a laser beam to a rear surface of thegrowth substrate 205, so that the interface between the growth substrate205 and the second conductive semiconductor layer 212 is delaminated.

As the growth substrate 205 is removed, the bottom surface of the secondconductive semiconductor layer 212 may be exposed. A wet etching processis performed with respect to the second conductive semiconductor layer212, thereby removing impurities remaining on the surface of the secondconductive semiconductor layer 212.

Referring to FIG. 17, an isolation etching is performed with respect tothe chip region of the light emitting structure 210, so that a pluralityof light emitting devices can be formed.

For example, the isolation etching process may be performed by using dryetching equipment such as ICP (Inductively Coupled Plasma) equipment.

Referring to FIG. 18, the passivation layer 235 may be formed on atleast a lateral surface of the light emitting structure 210.

In detail, one end of the passivation layer 235 may be provided on thetop surface of the light emitting structure 210, that is, the topsurface of the second conductive semiconductor layer 212, and anopposite end of the passivation layer 235 may be formed on theprotection layer 247 through the lateral surface of the light emittingstructure 210, but the embodiment is not limited thereto.

The passivation layer 235 may be formed through at least one of theE-beam deposition, the PECVD, and the sputtering.

Referring to FIG. 19, the adhesive layer 230 may be formed on the topsurface of the light emitting structure 210.

The adhesive layer 230 may be formed through at least one of the E-beamdeposition, the PECVD, and the sputtering. The adhesive layer 230 mayinclude the same material as that of the passivation layer 235 or mayinclude a material different from that of the passivation layer 235.

A roughness structure or a concave-convex structure may be formed on thetop surface of the light emitting structure 210, that is, the topsurface of the second conductive semiconductor layer 212 before theadhesive layer 230 has been formed.

A portion of the adhesive layer 230 is removed such that the electrode250 may contact the second conductive semiconductor layer 212.Accordingly, a portion of the second conductive semiconductor layer 212may be exposed.

Referring to FIG. 20, the electrode 250 is formed on the exposed regionof the second conductive semiconductor layer 212 of the light emittingstructure 210 and the adhesive layer 230, thereby providing the lightemitting device 200 according to the fifth embodiment. A portion of thebottom surface of the electrode 250 contacts the top surface of thesecond conductive semiconductor layer 212, and another portion of thebottom surface of the electrode 250 may contact the top surface and thelateral surface of the adhesive layer 230.

Since the bottom surface of the electrode 250 contacts the top surfaceand the lateral surface of the adhesive layer 230, the bottom surface ofthe electrode 250 may more firmly contact the top surface of the lightemitting structure 210.

FIG. 21 is a sectional view showing a light emitting device package 10having the light emitting device 100 according to the embodiment.

Referring to FIG. 21, the light emitting device package 10 includes abody 20, first and second lead electrodes 31 and 32 formed on the body20, the light emitting device 100 mounted on the body 20 andelectrically connected to the first and second lead electrodes 31 and 32and a molding member 40 that surrounds the light emitting device 100.

The body 20 may include silicon, synthetic resin or metallic material.The body 20 may be formed with an inclined inner wall around the lightemitting device 100.

The first and second electrode layers 31 and 32 are electricallyisolated from each other and supply power to the light emitting device100. The first and second lead electrodes 31 and 32 can reflect lightgenerated from the light emitting device 100 to increase lightefficiency and dissipate heat emitted from the light emitting device 100to the outside.

The light emitting device 100 can be installed on the body 20 or thefirst and second lead electrodes 31 and 32.

The light emitting device 100 may be electrically connected to the firstand second lead electrodes 31 and 32 through one of a wire, a flip-chipand a die bonding scheme.

The molding member 40 surrounds the light emitting device 100 to protectthe light emitting device 100. In addition, the molding member 40 mayinclude luminescent material to change the wavelength of the lightemitted from the light emitting device 100.

The light emitting device package may include at least one lightemitting device according to the embodiments or may include a pluralityof light emitting devices according to the embodiments, but thedisclosure is not limited thereto.

The light emitting device or the light emitting device package accordingto the embodiment may be applied to the light unit. The light unit hasan array structure of a plurality of light emitting devices or aplurality of light emitting device packages. The light unit may includethe display device as shown in FIGS. 22 and 23 and the lighting deviceas shown in FIG. 24. In addition, the light unit may include a lightinglamp, a signal lamp, a headlight of a vehicle, and an electricsignboard.

FIG. 22 is an exploded perspective view showing the display deviceaccording to the embodiment.

Referring to FIG. 22, the display device 1000 includes a light guideplate 1041, a light emitting module 1031 for supplying the light to thelight guide plate 1041, a reflective member 1022 provided below thelight guide plate 1041, an optical sheet 1051 provided above the lightguide plate 1041, a display panel 1061 provided above the optical sheet1051, and a bottom cover 1011 for receiving the light guide plate 1041,the light emitting module 1031, and the reflective member 1022. However,the embodiment is not limited to the above structure.

The bottom cover 1011, the reflective sheet 1022, the light guide plate1041 and the optical sheet 1051 may constitute a light unit 1050.

The light guide plate 1041 diffuses the light supplied from the lightemitting module 1031 to provide surface light. The light guide plate1041 may include transparent material. For instance, the light guideplate 1041 may include one of acryl-based resin, such as PMMA(polymethyl methacrylate, PET (polyethylene terephthalate), PC(polycarbonate), COC (cyclic olefin copolymer) and PEN (polyethylenenaphthalate) resin.

The light emitting module 1031 is disposed at one side of the lightguide plate 1041 to supply the light to at least one side of the lightguide plate 1041. The light emitting module 1031 serves as the lightsource of the display device.

At least one light emitting module 1031 is provided to directly orindirectly supply the light from one side of the light guide plate 1041.The light emitting module 1031 may include a substrate 1033 and lightemitting device packages 30 according to the embodiments. The lightemitting device packages 30 are arranged on the substrate 1033 whilebeing spaced apart from each other at the predetermined interval. Thesubstrate 1033 may include a printed circuit board (PCB), but theembodiment is not limited thereto. In addition, the substrate 1033 mayalso include a metal core PCB (MCPCB) or a flexible PCB (FPCB), but theembodiment is not limited thereto. If the light emitting device packages30 are installed on the side of the bottom cover 1011 or on a heatdissipation plate, the substrate 1033 may be omitted. The heatdissipation plate partially contacts the top surface of the bottom cover1011. Thus, the heat generated from the light emitting device packages30 can be emitted to the bottom cover 1011 through the heat dissipationplate.

In addition, the light emitting device packages 30 are arranged suchthat light exit surfaces of the light emitting device packages 30 arespaced apart from the light guide plate 1041 by a predetermineddistance, but the embodiment is not limited thereto. The light emittingdevice packages 30 may directly or indirectly supply the light to alight incident surface, which is one side of the light guide plate 1041,but the embodiment is not limited thereto.

The reflective member 1022 is disposed below the light guide plate 1041.The reflective member 1022 reflects the light, which travels downwardthrough the bottom surface of the light guide plate 1041, toward thedisplay panel 1061, thereby improving the brightness of the displaypanel 1061. For instance, the reflective member 1022 may include PET, PCor PVC resin, but the embodiment is not limited thereto. The reflectivemember 1022 may serve as the top surface of the bottom cover 1011, butthe embodiment is not limited thereto.

The bottom cover 1011 may receive the light guide plate 1041, the lightemitting module 1031, and the reflective member 1022 therein. To thisend, the bottom cover 1011 has a receiving section 1012 having a boxshape with an opened top surface, but the embodiment is not limitedthereto. The bottom cover 1011 can be coupled with the top cover (notshown), but the embodiment is not limited thereto.

The bottom cover 1011 can be manufactured through a press process or anextrusion process by using metallic material or resin material. Inaddition, the bottom cover 1011 may include metal or non-metallicmaterial having superior thermal conductivity, but the embodiment is notlimited thereto.

The display panel 1061, for instance, is an LCD panel including firstand second transparent substrates, which are opposite to each other, anda liquid crystal layer disposed between the first and second substrates.A polarizing plate can be attached to at least one surface of thedisplay panel 1061, but the embodiment is not limited thereto. Thedisplay panel 1061 displays information by blocking the light generatedfrom the light emitting module 1031 or allowing the light to passtherethrough. The display device 1000 can be applied to various portableterminals, monitors of notebook computers, monitors or laptop computers,and televisions.

The optical sheet 1051 is disposed between the display panel 1061 andthe light guide plate 1041 and includes at least one transmittive sheet.For instance, the optical sheet 1051 includes at least one of adiffusion sheet, a horizontal and vertical prism sheet, and a brightnessenhanced sheet. The diffusion sheet diffuses the incident light, thehorizontal and vertical prism sheet concentrates the incident light ontothe display panel 1061, and the brightness enhanced sheet improves thebrightness by reusing the lost light. In addition, a protective sheetcan be provided on the display panel 1061, but the embodiment is notlimited thereto.

The light guide plate 1041 and the optical sheet 1051 can be provided inthe light path of the light emitting module 1031 as optical members, butthe embodiment is not limited thereto.

FIG. 23 is a sectional view showing a display device according to theembodiment.

Referring to FIG. 23, the display device 1100 includes a bottom cover1152, a substrate 1120 on which the light emitting device packages 30are arrayed, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device packages 30 mayconstitute the light emitting module 1060. In addition, the bottom cover1152, at least one light emitting module 1060, and the optical member1154 may constitute the light unit (not shown).

The bottom cover 1151 can be provided with a receiving section 1153, butthe embodiment is not limited thereto.

The optical member 1154 may include at least one of a lens, a lightguide plate, a diffusion sheet, a horizontal and vertical prism sheet,and a brightness enhanced sheet. The light guide plate may include PC orPMMA (Poly methyl methacrylate). The light guide plate can be omitted.The diffusion sheet diffuses the incident light, the horizontal andvertical prism sheet concentrates the incident light onto the displaypanel 1155, and the brightness enhanced sheet improves the brightness byreusing the lost light.

The optical member 1154 is disposed above the light emitting module 1060in order to convert the light emitted from the light emitting module1060 into the surface light. In addition, the optical member 1154 maydiffuse or collect the light.

FIG. 24 is a perspective view showing a lighting device according to theembodiment.

Referring to FIG. 24, the lighting device 1500 includes a case 1510, alight emitting module 1530 installed in the case 1510, and a connectionterminal 1520 installed in the case 1510 to receive power from anexternal power source.

Preferably, the case 1510 includes material having superior heatdissipation property. For instance, the case 1510 includes metallicmaterial or resin material.

The light emitting module 1530 may include a substrate 1532 and lightemitting device packages 30 installed on the substrate 1532. The lightemitting device packages 30 are spaced apart from each other or arrangedin the form of a matrix.

The substrate 1532 includes an insulating member printed with a circuitpattern. For instance, the substrate 1532 includes a PCB, an MCPCB, anFPCB, a ceramic PCB, and an FR-4 substrate.

In addition, the substrate 1532 may include material that effectivelyreflects the light. A coating layer can be formed on the surface of thesubstrate 1532. At this time, the coating layer has a white color or asilver color to effectively reflect the light.

At least one light emitting device package 30 is installed on thesubstrate 1532. Each light emitting device package 30 may include atleast one LED (light emitting diode) chip. The LED chip may include anLED that emits the light of visible ray band having red, green, blue orwhite color and a UV (ultraviolet) LED that emits UV light.

The light emitting device packages 30 of the light emitting module 1530can be variously arranged to provide various colors and brightness. Forinstance, the white LED, the red LED and the green LED can be arrangedto achieve the high color rendering index (CRI).

The connection terminal 1520 is electrically connected to the lightemitting module 1530 to supply power to the light emitting module 1530.The connection terminal 1520 has a shape of a socket screw-coupled withthe external power source, but the embodiment is not limited thereto.For instance, the connection terminal 1520 can be prepared in the formof a pin inserted into the external power source or connected to theexternal power source through a wire.

According to the embodiment, in the light emitting device, the adhesivelayer is provided on the semiconductor layer, and the electrode isprovided on the top surface of the semiconductor layer and on the topsurface and the lateral surface of the adhesive layer. The adhesivelayer having stronger adhesive strength is provided between thesemiconductor layer and the electrode, so that the electrode can beprevented from getting out of the light emitting structure. Therefore,the product reliability can be improved.

According to the embodiment, a concave-convex structure is formed on thetop surface and the bottom surface of the adhesive layer, so that theadhesive strength can be more firmly enhanced. Accordingly, the productreliability can be maximized.

According to the embodiment, the electrode overlaps with the adhesivelayer perpendicularly to the adhesive layer, so that the contact area ofthe electrode is expanded. Accordingly, the adhesive strength can bemore improved.

According to the embodiment, when the adhesive layer includes conductivematerial, the adhesive layer is provided only on the semiconductorlayer, so that the layers of the light emitting structure can beprevented from being shorted with each other.

According to the embodiment, the adhesive layer is provided on the topsurface and the lateral surface of the first conductive semiconductorlayer, on the lateral surface of the active layer, and on the lateralsurface and the top surface of the second conductive semiconductorlayer, so that the lateral surfaces of the light emitting structure canbe protected.

According to the embodiment, in the structure of the vertical type lightemitting device, the passivation layer is formed on the lateral surfaceof the light emitting structure, and the adhesive layer extends from thepassivation layer, so that the manufacturing process can be simplified.

According to the method of manufacturing the light emitting device ofthe embodiment, a light emitting structure including the firstconductive semiconductor layer, the active layer, and the secondconductive semiconductor layer is formed on the substrate, an etchingprocess is performed to expose a portion of the first conductivesemiconductor layer, an adhesive layer is formed on at least the topsurface of the first conductive semiconductor layer, a portion of theadhesive layer is removed to expose the first conductive semiconductorlayer, and the electrode is formed on the top surface of the firstconductive semiconductor layer and on the top surface and the lateralsurface of the adhesive layer.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting device, comprising: a lightemitting structure including a first conductive semiconductor layer, anactive layer on the first conductive semiconductor layer, and a secondconductive semiconductor layer on the active layer; an electrode layeron the second conductive semiconductor layer; an insulating layer on thesecond conductive semiconductor layer; a first electrode on the firstconductive semiconductor layer; and a second electrode on the secondconductive semiconductor layer and the electrode layer, wherein theelectrode layer has a hole, and the second electrode contacts the secondconductive semiconductor layer through the hole of the electrode layer,wherein the second electrode comprises an upper portion and a lowerportion under the upper portion, wherein the lower portion has a sidesurface encompassed by an interior surface of the hole of the electrodelayer, and wherein the insulating layer contacts at least a top surfaceof the second conductive semiconductor layer.
 2. The light emittingdevice of claim 1, wherein the insulating layer includes at least oneselected from the group consisting of SiO2, SiOx, SiOxNy, Si3N4, TiO2and Al2O3.
 3. The light emitting device of claim 1, wherein theelectrode layer comprises ITO.
 4. The light emitting device of claim 1,wherein the lower portion of the second electrode has a width smallerthan a width of the second electrode.
 5. The light emitting device ofclaim 1, wherein the insulating layer overlaps at least a portion of theelectrode layer.
 6. The light emitting device of claim 1, wherein theinsulating layer contacts at least a top surface of the electrode layer.7. The light emitting device of claim 1, wherein the insulating layerextends from the first electrode to a portion of a top surface of thesecond conductive semiconductor layer.
 8. The light emitting device ofclaim 1, wherein the second electrode comprises a multiple layerstructure that includes at least two or more selected from the groupconsisting of Au, Al, Cr, Ag, Ti, Cu and Ni.
 9. The light emittingdevice of claim 1, wherein the electrode layer comprises at least onestepped portion.
 10. A light emitting device, comprising: a lightemitting structure including a first conductive semiconductor layer, anactive layer on the first conductive semiconductor layer, and a secondconductive semiconductor layer on the active layer; an electrode layeron the second conductive semiconductor layer; an insulating layer on thesecond conductive semiconductor layer; a first electrode on the firstconductive semiconductor layer; and a second electrode on the secondconductive semiconductor layer and the electrode layer, wherein theelectrode layer has a hole, and the second electrode contacts the secondconductive semiconductor layer through the hole of the electrode layer,wherein the second electrode has a bottom surface that comprises aprotrusion, wherein protrusion has a side surface surrounded by an innersurface of the hole of the electrode layer, and wherein the insulatinglayer contacts at least a top surface of the electrode layer or at leasta top surface of the second conductive semiconductor layer.
 11. Thelight emitting device of claim 10, wherein the insulating layer includesat least one selected from the group consisting of SiO2, SiOx, SiOxNy,Si3N4, TiO2 and Al2O3.
 12. The light emitting device of claim 10,wherein the electrode layer comprises ITO.
 13. The light emitting deviceof claim 10, wherein the protrusion of the second electrode has a widthsmaller than a width of the second electrode.
 14. The light emittingdevice of claim 10, wherein the insulating layer overlaps at least aportion of the electrode layer.
 15. The light emitting device of claim10, wherein the insulating layer extends from the first electrode to aportion of a top surface of the second conductive semiconductor layer.16. The light emitting device of claim 10, wherein the second electrodecomprises a multiple layer structure that includes at least two or moreselected from the group consisting of Au, Al, Cr, Ag, Ti, Cu and Ni. 17.The light emitting device of claim 10, wherein the electrode layercomprises at least one stepped portion.
 18. A light emitting device,comprising: a light emitting structure including a first conductivesemiconductor layer, an active layer on the first conductivesemiconductor layer, and a second conductive semiconductor layer on theactive layer; an electrode layer on the second conductive semiconductorlayer; a first electrode on the first conductive semiconductor layer;and a second electrode on the second conductive semiconductor layer andthe electrode layer; and an insulating layer on the light emittingstructure between the first electrode and the second electrode, whereinthe electrode layer has a hole, and the second electrode contacts thesecond conductive semiconductor layer through the hole of the electrodelayer, wherein the second electrode comprises an upper portion and alower portion under the upper portion, wherein the lower portion has aside surface encompassed by an interior surface of the hole of theelectrode layer, and wherein the insulating layer contacts the secondconductive semiconductor layer and the electrode layer.
 19. The lightemitting device according to claim 18, wherein the insulating layerincludes SiO2, and the electrode layer comprises ITO.
 20. The lightemitting device of claim 18, wherein the electrode layer comprises atleast one stepped portion.
 21. A light emitting device, comprising: alight emitting structure including a first conductive semiconductorlayer, an active layer on the first conductive semiconductor layer, anda second conductive semiconductor layer on the active layer; anelectrode layer on the second conductive semiconductor layer; aninsulating layer on the second conductive semiconductor layer; a firstelectrode on the first conductive semiconductor layer; and a secondelectrode on the second conductive semiconductor layer and the electrodelayer, wherein the electrode layer has a hole, and the second electrodecontacts the second conductive semiconductor layer through the hole ofthe electrode layer, wherein the second electrode comprises an upperportion and a lower portion under the upper portion, wherein the lowerportion has a side surface encompassed by an interior surface of thehole of the electrode layer, and wherein a first portion of theinsulating layer extends from the first electrode to a portion of a topsurface of the second conductive semiconductor layer.
 22. The lightemitting device according to claim 21, wherein a second portion of theinsulating layer is disposed on the second conductive semiconductorlayer, and wherein the second portion of the insulating layer isprovided between the second conductive semiconductor layer and theelectrode layer.
 23. The light emitting device of claim 21, wherein thefirst portion of the insulating layer does not overlap with the hole ofthe electrode layer.
 24. The light emitting device of claim 21, whereinthe electrode layer comprises at least one stepped portion.